Solar energy systems are used to collect solar radiation and convert it into useable electrical energy. A system typically includes an array of solar energy units mounted on a tracker and a controller directing the tracker via a drive motor. Automated tracker controllers for solar energy systems are used to direct solar energy units to follow the path of the sun. The controller generally relies on the precise and accurate position of the tracker, a clock or timing mechanism and the ephemeris equation to calculate the relative direction of the solar radiation with respect to an array of solar energy units. Controllers typically control a single tracker that may support one or more arrays of solar energy units. A solar energy unit may be a concentrating photovoltaic (CPV) solar energy device, which is a device that utilizes one or more optical elements to concentrate incoming light onto a photovoltaic cell. This concentrated light, which may exhibit a power per unit area of 500 or more suns, relies on precise orientation to the sun in order to provide improved performance.
One or more CPV devices may be assembled into an array. Such arrays are mounted on a tracking apparatus that may include a rigid support structure, drive motors, and cooling mechanisms. Trackers may pivot and rotate several solar energy arrays simultaneously to follow the path of the sun. Trackers are typically distributed relative to one another in such a way as to provide a maximum exposure to sunlight while minimizing the shade profile that one array may have on another. This results in a sparse distribution of trackers in a field. Distribution may be measured as two-dimensional ground cover density (GCD2D). Improvements are needed in order to provide a denser distribution of trackers to maximize the amount of solar energy collected per area.
Periodically individual solar energy systems in a field may break down. The resulting inoperative tracker or solar energy device may generate shade on nearby arrays as the sun changes elevation. Consequently, performance in neighboring solar energy systems may be reduced. The shade patterns of surrounding structures (e.g., wind turbines, buildings, landscape elements and trees) may also impact the maximum possible power output of a field of solar energy systems. Current tracker controllers do not account for elements in the landscape that may periodically block solar radiation, such other trackers, trees, buildings or inoperative trackers. Furthermore, trackers designed to maximize power output at the array level can result in sub-optimal power generation of the field as a whole.
Thus, there exists a need for improved tracker controllers which enable a denser distribution of solar energy systems and provide dynamic control of individual trackers in order to maximize the power output of a field of solar energy systems.